SOME OF YOUR VEHICLES MAY HAVE BEEN ALTERED BY PREVIOUS OWNERS.

Here are some original wiring diagrams and images that may help you return it to the correct state. These are typical of the ignition circuits on OPUS equipped V12's. Many early systems may have been changed by dealers/service agents to a later system. This was an attempt to cure the problems Jaguar had with the OPUS ignition system. Consequently, you may have either early colour-banded black wiring or the later self-coloured wiring. To print these pages, it's best to save a .pdf version to your computer here If you do not have the free Adobe Acrobat .pdf reader, download it from here

Early type wiring diagram:

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EARLY TYPE ALL-BLACK WIRING.
NOTE SMALL COLOUR CODE BANDS ON WIRES!

(These are often hidden under white rubbery material on original circuit boards)
Be careful not to lose any bands or overlook any of the Black Bands on Black wires (difficult to spot).
Later type had self-coloured wires. (See below)


 

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Later type wiring diagram:

IMPORTANT NOTE: The wiring diagram shows two WU wires to the ballast resistor pack.
Close examination will show that the conventional WU, i.e. the one which is white with a straight blue stripe, is the one supplying power from the starter relay
( # 194 on the wiring diagram below). This goes to the "START" position.
The wire for the tachometer is the other WU, and is the one in which the blue stripe SPIRALS on the white. It may also be White/Slate instead of White/Blue.
Remember, your vehicle may only have five wires going into the amplifier and it is best to keep it this way. The tachometer may have been converted to run direct from the coil.

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Below is a section from XJ12 SII Wiring diagram (with key below) showing relevant details. Other OPUS equipped vehicles will be similar.

 

 

 

 

Early type OPUS from V12 E-type. NOTE: Red coloured PC board compared to later type green board


 

Later type OPUS from XJ-S showing self-coloured wires NOTE: Lack of White/Blue wire due to different Tachometer driving arrangement.

 

 

 

 

Photo of Starter Solenoid/Ballast Coil Relay from XJ12 SII. Again, other vehicles will be similar.

 

 

 

 

 

Typical Ballast Resistor Pack with Coil bolted over top. NOTE: inputs stamped on casing - SII XJ12. In this photo, wiring to coil is NOT original, however the white/blue-spiral wire for the tachometer is typical. Later wiring harnesses may substitute this wire with white/slate.

WE WOULD WELCOME PHOTOS, DIAGRAMS, NOTES, ETC., OF ANY INSTALLATION YOU HAVE THAT MIGHT HELP OUR CUSTOMERS IN THE FUTURE.

 

MORE ON COLOUR CODES

British vehicles used colour coded wiring to help identify various circuits employed. This is from BS-AU7a 1983 Colour Code for Vehicle Wiring, from the British Standards Institution.

(These colour codes may not be totally applicable to older cars. However, the tables are a pretty good guide).

MAIN
TRACER
PURPOSE
Black
All earth connections
Black
Brown
Tachometer generator to tachometer
Black
Blue
Tachometer generator to tachometer
Black
Red
Electric or electronic speedometer to sensor
Black
Purple
Temperature switch to warning light
Black
Green
Relay to radiator fan motor
Black
Light green
Vacuum brake switch or brake differential pressure valve to warning light and/or buzzer
Black
White
Brake fluid level warning light to switch and handbrake switch, or radio to speakers
Black
yellow
Electric speedometer
Black
Orange
Radiator fan motor to thermal switch

MAIN
TRACER
PURPOSE
Blue
Lighting switch (head) to dip switch
Blue
Brown
Headlamp relay to headlamp fuse
Blue
Red
Dip switch to headlamp dip beam fuse
Fuse to right-hand dip headlamp
Blue
Light green
Headlamp wiper motor to headlamp wash pump motor
Blue
White
a) Dip switch to headlamp main beam fuse
b)Headlamp flasher to main beam fuse
c)Dip switch main beam warning light
d)Dip switch to long-range driving light switch
Blue
Yellow
Long-range driving light switch to lamp
Blue
Black
Fuse to right-hand main headlamp
Blue
Pink
Fuse to left-hand dip headlamp
Blue
Slate
Headlamp main beam fuse to left-hand headlamp or inboard headlamps when independently fused
Blue
Orange
Fuse to right-hand dip headlamp

MAIN
TRACER
PURPOSE
Brown
Main battery lead
Brown
Blue
Control box (compensated voltage control only) to ignition switch and lighting switch (feed)
Brown
Red
Compression ignition starting aid to switch
Main battery feed to double pole ignition switch
Brown
Purple
Alternator regulator feed
Brown
Green
Dynamo 'F' to controlboxl 'F'
Alternator field 'F' to control box 'F'
Brown
White
Ammeter to control box
Ammeter to main alternator terminal
Brown
Yellow
Alternator to 'no charge' warning light
Brown
Black
Alternator battery sensing lead
Brown
Slate
Starter relay contact to starter solenoid
Brown
Orange
Fuel shut-off (diesel stop)

MAIN
TRACER
PURPOSE
Green
Accessories fused via ignition switch
Green
Brown
Switch to reverse lamp
Green
Blue
Water temperature gauge to temperature unit
Green
Red
Direction indicator switch to left-hand flasher lamps
Green
Purple
Stop lamp switch to stop lamps, or stop lamp switch to lamp failure unit
Green
Light green
Hazard flasher unit to hazard pilot lamp or lamp failure unit to stop lamp bulbs
Green
White
Direction indicator switch to right hand flasher lamps
Green
Yellow
Heater motor to switch single speed (or to 'slow' on two or three-speed motor)
Green
Black
Fuel gauge to fuel tank unit or changeover switch or voltage stabilizer to tank units
Green
Pink
Fuse to flasher unit
Green
Slate
a)Heater motor to switch ('fast' on two- or three-speed motor)
b)Coolant level unit to warning light
Green
Orange
Low fuel level switch to warning light

MAIN
TRACER
PURPOSE
Light Green
Instrument voltage stabilizer to instruments
Light green
Brown
Flasher switch to flasher unit
Light green
Blue
a)Flasher switch to left-hand flasher warning light
b)Coolant level sensor to control unit
c)Test switch to coolant level control unit
Light green
Red
Fuel tank changeover switch to right-hand tank unit or entry and exit door closed switch to door actuator
Light green
Purple
Flasher unit to flasher warning light
Light green
Green
Start inhibitor relay to change speed switch; or switch to heater blower motor second speed on three-speed unit
Light green
White
Low air pressure switch to buzzer and warning light
Light green
Yellow
Flasher switch to right-hand warning light; or differential lock switch to differential lock warning light
Light green
Black
Front screen jet switch to screen jet motor
Light green
Slate
Fuel tank changeover switch to left-hand tank unit; or entry and exit door open switch to door actuator
Light green
Orange
Rear window wash switch to wash pump; or cab lock-down switch to warning light

MAIN
TRACER
PURPOSE
Orange
Wiper circuits fused via ignition switch
Orange
Blue
Switch to front screen wiper motor first speed timer or intermittent unit
Orange
Green
Switch to front screen wiper motor second speed
Orange
Black
Switch to front screen wiper motor parking cicuit, timer or intermittent unit
Orange
Purple
Timer or intermittent unit to motor parking circuit
Orange
White
Timer or intermittent unit to motor parking circuit
Orange
Yellow
Switch to headlamp or rear window wiper motor feed, timer or relay coil
Orange
Light green
Switch to headlamp or rear window wiper motor parking circuit timer or relay coil
Orange
Pink
Timer or relay to headlamp or rear window wiper motor feed
Orange
Slate
Timer or relay to headlamp or rear window wiper motor parking circuit

MAIN
TRACER
PURPOSE
Pink
White
Ballast terminal to ignition distributor

MAIN
TRACER
PURPOSE
Purple
Accessories fed direct from battery via fuse
Purple
Brown
Horn fuse to horn relay when horn is fused separately
Purple
Blue
Fuse to heated rear window relay or switch and warning light
Purple
Red
Switches to map light, under bonnet light, glove box light and boot lamp when fed direct from battery fuse
Purple
Green
Fuse to hazard flasher
Purple
Light green
Fuse to relay for screen demist
Purple
White
Interior lights to switch (subsidiary circuit door safety lights to switch)
Purple
Yellow
Horn to horn relay
Purple
Black
Horn to horn relay to horn push
Purple
Pink
Rear heated window to switch or relay
Purple
Slate
Aerial lift motor to switch up
Purple
Orange
Aerial lift motor to switch down

MAIN
TRACER
PURPOSE
Red
Main feed to all circuits mastered by sidelamp switch
Red
Brown
Rear fog guard switch to lamps
Red
Blue
Front fog lamp fuse to fog lamp switch
Red
Purple
Switches to map light, under bonnet light, glove box light and boot lamp when sidelamp circuit fed
Red
Green
Bulb failure unit to right-hand-side and rear lamps
Red
White
a)Sidelamp fuse to right-hand side and rear lamps
b)Sidelamp fuse to panel light rheostat
c)Fuse to panel light switch or rheostat
d)Fuse to fibre optic source
Red
Yellow
Fog lamp switch to fog lamp or front fog fuse to fog lamps
Red
Black
Left-hand,sidelamp fuse to side and tail lamps and number plate illumination
Red
Pink
Sidelamp fuse to lighting relay
Red
Slate
Lamp failure unit to lef-hand side and tail lamps
Red
Orange
Fusebox to rear fog guard switch

MAIN
TRACER
PURPOSE
Slate
Window lift main lead

MAIN
TRACER
PURPOSE
White
Ignition switch or starter solenoid to ballast resistor
White
Brown
Oil pressure switch to warning light or gauge, or starter relay to oil pressure switch
White
Blue
Choke switch to choke solenoid (unfused) and/or choke to switch to warning light, or electronic ignition distributor to drive resistor
White
Red
Starter switch to starter solenoid or inhibitor switch or starter relay or ignition (start position) to bulb failure unit
White
Purple
Fuel pump no 1 or right-hand to changeover switch
White
Green
Fuel pump no 2 or left-hand to changeover switch
White
Light green
Start switch to starter interlock or oil pressure switch to fuel pump or start inhibitor switch to starter relay or solenoid
White
Yellow
Ballast resistor to coil or starter solenoid to coil
White
Black
Ignition coil contact breaker to distributor contact breaker, or distributor side of coil to voltage impulse tachometer
White
Pink
Ignition switch to radio fuse
White
Slate
Current tachometer to ignition coil
White
Orange
Hazard warning lead to switch

MAIN
TRACER
PURPOSE

Yellow

a)Overdrive

b)Petrol injection
c)Door locks
d)Gear selector switch to start